Colored concrete



106. COMPOSITIONS, g g 9 OCOATING R PLASTIC.

Patented Sept. 4, 1934 COLORED coNcRETE George orth Andover, Mass.; Charles j W. Tucker administrator of said George R. fi/ 44 Tucker, deceased No Drawing. Application December 12, 1932,

Serial No. 646,876 g.

21 Claims. (Cl. 106-24) This invention relates to the coloring of plasin straight chain or branched chain formation; tic masses such as concrete prepared from the and in which $03M designates at least one free two essential ingredients water and a calcareous sulw or at leasLone sulfonic acid substance such as hydraulic cement ie. Portgroup in combination with We 5 an cemen ca cine sum ime, clay, or the radical. The members of t e class may be n- I 0 Am 8, with or without inert bulkin or filhn rnathesized either by direct sulfonation of a hydroterials' and it comprises among its OBJGCES the Carbon or a derivative thereof which possesses production of more brilliant hues than have forthe necessary configuration of Wmmerly been attainable in materials of this charthalene rings joii epl tg an aliphatic nucleus or.

acter, a reduction in the quantity of pigment esaililgllfllllmQILBJORVEIQQIllLMZQEQL IELCLtlU sential to produce a given color intensity, and pmgtical bynansingkanaphthalene sulfonic aci d the production of colored objects of the type deorgashomologuuon dfirwwig scribed with no such diminution in strength as witll iu imaldfihy e or its equivalent; pgeferably I has heretofore accompanied the introduction of i thgratloiflwgximately two mols oj arg- Y 1 15 pigments thereinto. matic sulfonic acid for each mnl nf aldehvde,

It is well known that the introduction of many The member of the family which I generally emfinely divided pigments into concrete results in ploy because it is cheap and very effective for a greater reduction in strength than the bulking present purposes may be obtained by condensing influence of the structurally inert pigment ocbeta-naphthalene sulfonic acid with formalde- 20 casions. It is also well known that pigments hyde. While the beta-naphthalene sulfonic acid usually possess less tinctorial power when used condensation product may be prepared in known in concrete than when employed in more comways, I find that the product obtained by followpatible environments. Furthermore, some of the ing the procedure set forth in my co-pending ap- .insoluble coloring materials which for most purplication Serial No. 643,743, filed November 21,

5 poses possess by far the greatest tinctorial or 001- 1932, and given below possesses highly satisfacoring power are precluded from use in concrete tory properties for use in practicing my invention. because of the extraordinary extent to which To 100 parts of concentrated sulfuric acid (spethey decrease the strength of the hardened macific gravity 1.84) con ained in a sui ab e su onaterial. Anexcellent example of this latter class tor and maintained at 160 C are added slowly 30 of substances is carbon black which, when used with stirring 100 parts of refined na hthalene. in amounts mum the weight of the After all of the naphthalene has been introduced calcareous constituent, e. g. Portland cement, of (this operation generally requires about one hour) the concrete, efiects about a 30% reduction in the the mass is stirred at 160 C. for four hours longer compressive strength of the hardened concrete. or until a test shows that substantially none of 35 I have discovered that colored concretes posthe naphthalene remains unsulfonated. The sul- 9Q sessing greater brilliancy, greater color intensity fonation mixture is then cooled to about 100 C. for a given quantity of pigment, and greater and diluted with 44 parts of water to prevent strengths than have heretofore been possible unsolidification on subsequent cooH'n g'. "Ihe diluted der otherwise like conditions may be obtained material is further cooled to 80 C. at which tem- 40 with the aid of a small amount of a soluble derivperature 12 parts of a 40% aqueous solution of ative, or even the free sulfonic acid, of a sulfonic formaldeh de are added. I'Hls mixture is then acid chosen from a certain class of aromatic sulstirred tor three hours longer at 80 C.; but at the tonic acids. This class broadly embraces the end of each successive hour there are added 12 compounds of the general structure obtained by parts more of formaldehyde solution, making a 45 condensing sulfonic acids of naphthalene, its total at the end of the three hours of four portions homologues or derivatives, with formaldehyde or or 48 parts in all. Af a e formaldehyde has 1 s equiva en Tiese compoun s may e 00 ed been added, the temperature is progressively raised upon as derivatives of polynaphthyl alkyls or over a period of one hour to g 5-10QlC. where it is their homologues and may be expressed by the maintained for 18 hours, whil'ethd'hass is con- 50 general graphical formula (A.RA)SO3M in stantly stirred, or until the control test. described which A and A designate two or more aromatic later on in this specification shows that a product groupswhich may or may not be alike; which of optimum effectiveness has been obtained. EX- contain naphthalene rings joined to an aliphatic perience has shown that when pure naphthalene is nucleus R which may consist of a single alkyl used, a final heating period of 18 hours yields the 5 group or a plurality of alkyl groups associated best product. Soon after the temperature has been raised to 95-100 (1., it is found that substanspecification; but this theory forms no part of tially none of the aldehyde remains unconsumed my definition and I do not desire to be bound in the condensation reaction. During the later by it. stages of the 18-hour heating period, the mixture Whereas I commonly use and particularly recprogressively thickens until at the end it generally ommend the use of the sulfonic acid in the form reaches the consistency of thick molasses. If this of its sodium salt, any ETFBiHfiiiitiVe which is thickening becomes so great, however, as to presoluble in the aqueous environment of concrete, vent proper stirring, a small quantity of water may v theiree, @915 y be p y Thus, be added to keep the material liquid. After the for example, the calcium saltlssufiiciently soluheating is completed, the mixture is cooled, neuble for present purposes and may sometimes be tralized with a suitable alkali, e. g. sodium h used with advantage because it is cheaper to droxide, and, if desired, dried. It is then ready prepare and is quite compatible with concrete or use. which itself may normally contain water-soluble A somewhat purer and better product can be calcium salts. I wish it to be understood, howobtained by diluting the viscous reaction mass ever, that when I specify a soluble compound or with about three times its volume of water (the derivative, I intend to denote a material which amount is not importantsolong as it is sufficient to is soluble in the aqueous environment of conpermit convenient handling in the subsequent crete; and the generic term derivative I intend filtering operation), and neutralizing with lime. to comprise the specific chemical class of ma- For the latter purpose I generally use an aqueous terials known as salts. paste or suspension of h drated or slaked lime. In the practice of my invention the active The neutralized slurry is filtered Ho t to remove"' agent, which may be any one chosen from the the calcium sulfate precipitate which forms from broad class defined above, may be added in the the interaction of the lime and sulfuric acid un- 'tion to the finely divided consumed in the sulfonation reaction; and to the pigment dry mixture a e o e mfiltrate is added the requisite amount of sodium gre 1cm in the concrete mixer in the usual mancarbonate quantitatively to convert the calcium ner; or the two constituents may be added sepasalt of the desired sulfonic acid into its sodium rately to the concrete mix such as when the salt. The resulting calcium carbonate precipitate agent is dissolved in the mixing water and the may then be removed by filtration and the filtrate dry pigment added to the other dry ingredients; which contains the desired ingredient evaporated or the dry coloring material and agent may be to dryness according to any of the well known mixed or ground with the calcareous substance drying procedures.

The sulfonation of the naphthalene may be conducted in a cast iron vessel; but the reaction with formaldehyde is preferably carried out in enameledor lead-lined apparatus.

A cheap grade of crude naphthalene which contains other aromatic hydrocarbons as impurities may be employed in the foregoing detailed procedure without sacrifice of desirable qualities. The substitution of an alkylated naphthalene, e. g. a methyl naphthalene or an ethyl naphthalene for nmsults mm is particularly effective for present purposes. Such alkylated products, however, which are especially effective for use in the broader aspects of this invention, may be objectionable for some purposes because, due to their tendency to reduce the surface tension of water, they promote the formation of foam in the wet colored concrete. Materials made from aromatic compounds which are free from substituting alkyl groups have substantially no tendency to reduce the surface tension of water; and for this reason colored concretes prepared with them do not have the undesirable tendency to form foam in the wet state possessed by colored concretes prepared with the aid of prior pigment dispersing agents which, unlike present materials, generally rely for their effectiveness on their ability to reduce the surface tension of water. The product obtained as described above by the reaction 0 napht lgne sulfo r iicacid with formaldehyde isspeci cally recommended for use in a prefer red form of this invention where the tendency to produce foam is objectionable.

In the chemical reaction which occurs between an aromatic sulfonic acid and formaldehyde or its equivalent, it is my theory that the initial condensation reaction is followed by a progressive polymerization of the resulting condensed niaterial, and that a certain optimum molecular weight is necessary to yield the best results for present purposes as determined according to the indicated empirical test given later on in this in the process of its manufacture, e. g. they may be ground Ftp, Portland cement clinker or with ihe ms e cemen a e m or e pigmen e a e ay 0 he concrete ingredients as an aqueous slurry or paste prepared with the aid of one of the above described agents. An advantageous result is obtained in every case; but I prefer the procedure wherein the pigment and agent are incorporated with the dry calcareous substance in the process of its manufacture, e. g. where the addition is made to tube mills in which Portland cement is ground. When the coloring material is added as an aqueous paste, it is desirable to prepare the pastejgy grinding the pigment as in a ball or colloid mill in the presence of a solution of the active agent. Other methods or modifications of the indicated methods of incorporating the coloring material in accordance with this invention will be apparent to those skilled in the art.

The appropriate quantity of any agent selected from the defined class to be used for any given pigment may be ascertained by the following simple test. The exact amount of water required to convert 100 grams of the pigment into a stiff relatively dry paste or dough (of chosen consistency) is carefully determined. The precise consistency chosen is not important as it is merely to be used for comparative purposes; but the water-pigment ratio must be accurately adhered to throughout the entire series of comparative tests described below. In like portions of water as ascertained above are then dissolved progressively ascending amounts of the agent to be tested, for example 1-, 2-, 3-, 4-, and 5-gram portions respectively. To each of these solutions is then added 100 grams of pigment and the mixture kneaded or stirred in a manner simulating as closely as possible the procedure employed in the original preparation of the pigment-water mixture, the consistency of which is to serve as the standard of comparison. The effect of the added ingredient is I06. COMPOSITIONS,

COATING OR PLASTIC.

to increase the fluidity of the pigment paste and that minimum quantity of agent should be chosen which is essential to produce the maximum improvement in fluidity. A larger quantity of agent is not harmful but possesses no particular advantage. For most purposes it will be found that 1-4 parts of the active agent for every 100 parts of the pigment will give the best results. As previously stated, this test is also useful to ascertain and control the optimum degree of polymerization of products made according to the general preparative procedure given above as well as to determine the relative value for present purposes of any material which falls within the scope of the appended claims.

This invention is not equally well adapted for use with all pigments. It is most effective with very finely divided pigments such as carbon black which are of strictly colloidal dime $10 which tend to form groups or aggregates when stirred into water; and it is least effective with coarse pigments which respond only slightly if at all, to colloid forces. The extent to which any pigment is benefited may be judged without resort to the actual practice of this invention from the improvement in fluidity which the added agent occasions in the pigment paste of the test described above. If the increase in fluidity is large, the process of this invention will correspondingly greatly enhance the coloring or tinctorial power of the pigment when used in concrete; but if the increase in fluidity is rela-- tively slight, the improvement afforded hereunder will be correspondingly small. Similarly, the degree of improvement may be predicted from a comparison under the microscope of two exactly similar aqueous pigment dispersions except that one contains the added agent. If the latter material causes the pigment particles to exist as individually dispersed particles engaged in Brownian movement, whereas in the absence of the agent the particles are aggregated and dead, i. e. display little or no Brownian motion, the process of this invention possesses ad- "the pigments such as vantages for use with the pigment under observation. Besides carbon black my discovery has proved especially effec ive or use with the various colored finely divided iron oxides or ochres and e a esw 1c are, in the process of their manufacture, precipitated as finely divided materials from aqueous media.

Colored concrete prepared with the aid of this invention possesses a brighter and deeper hue than do otherwise similar materials. Thus, for example, a concrete which contains 3% of carbon black together with one of the above described agents is quite equal in depth of hue to one which contains 5% introduced without the aid of this invention and the former has a brighter and glossier appearance than the latter. Similarly, 4% of red iron oxide incorporated in accordance herewith is equivalent to 6% without the aid of one of the stated agents.

But the process of this invention not only enables the production of deeper and brighter hues than are otherwise obtainable under like conditions; but it also substantially offsets in some manner which is not fully understood, for, as explained in my copending applications Serial Nos. 643,740, 643,741 and 643,742, filed November 21, 1932, the agents employed herein do not per se necessarily increase the strength of concrete, the abnormal decrease in strength which many finely divided pigments occasion when introduced into concrete. Whereas a quantity of carused in concrete have-a-hegeficial influence on concrete itself ir f w e er coloring materials are present or not. This general improvement forms the subject matter of my copending application Serial No. 643,742, filed N0 vember 2 1 1 fluidit 7 e plastic material w ch enables it to be handled mo when it is desired to work to a given workability or slump (a well known measure of workability used in the trade), permits either a reduction in..;

t uantity of A accompanying increase ifistrength or the emwater ratio and workability or slump are maintained. All these advantages also obtain in the present invention. Hence colored concretes prepared hereunder to a given formula are more workable and fiuid than otherwise similar ma terials prepared according to the same formula; or colored concretes made to a given workability by decreasing the amount of mixing water are stronger than otherwise like masses made to the same workability; or colored concretes mixed to a given water ratio and workability by employing arigtiws are cheaper than those ma e to the same water ratio and workability without the advantages of this invention and are fully equal to the latter in strength. .4

I am aware that protective colloids such as glue and casein have been added to pigments to improve their tinctorial power when used in aqueous media; but none of these, so far as I am informed, is particularly effective for use with pigments which are to be used in concrete. The reason for this is believed to be due to the fact that soluble constituents of concrete such as calcium or magnesium ions react with the ordinary protective coilloids to offset or destroy their protective influence. Furthermore, colloids of the mentioned class are generally objectionable for use with concrete because, as is well known, they usually injure the compressive strength thereof. In contradistinction to this, the agents which I employ are not markedly adversely influenced by any of the constituents of concrete and do not exert an injurious influence on the compressive strength of hardened concrete; and whereas it is thought that the advantages of this invention accrue from the dispersing effect of the herein described agents upon the pigment particles, the behavior of these agents is anomalous if this hypothesis is correct, because the usual dispersing agents are not satisfactory for my purposes,

The term concrete as employed herein is used in a broad generic sense which is intended to cover the initially plastic building materials,

whether in the fresh condition or the hardened state, which are prepared from the two essential ingredients water and a calcareous substance such as hydraulic cement (e. g. Portland cement), calcined gypsum, liine, clay, or the like, with or egg. It consists in an increase. in the with a well known I without bulking or filling materials such as sand joined to the same carbon atom of an aliphatic gravel, crus e s one, co e, as es s, an a in s o rous ma eria, e commo y used in articles of this character. And the term formaldehyde as used in the appended claims is intended to include as obvious chemical equivalents thereof compounds which are known to liberate, or act in the same way as, formaldehyde under the reaction conditions described in this specification or which are known to provide reactive methylene groups like the methylene group in formaldehyde.

Attention is directed to my copending application Ser. No. 646, 877.

It should be understood that the present disclosure is for the purpose of illustration only, and this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. The process of preparing colored concrete which comprises mixing water, a calcareous substance, and a finely divided coloring material in the presence of a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

2. The process of preparing colored concrete which comprises mixing water, a calcareous substance, and a finely divided coloring material in the presence of a soluble sulfonic acid derivative of a compound having at least two naphthalene rings joined to the same carbon atom of an aliphatic nucleus.

3. The process of preparing colored concrete which comprises mixing water, hydraulic cement, and a finely divided coloring material in the presence of a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

4. The process of preparing colored concrete which comprises mixing water, hydraulic cement, and carbon black in the presence of a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

5. The process of preparing colored concrete which comprises mixing water, hydraulic cement, and finely divided iron oxide in the presence of a soluble compound obtained by condensing form- 1. was

aldehyde with a sulfonic acid of the naphthalene series.

6. The process of preparing colored concrete which comprises mixing water, hydraulic cement, and a finely divided coloring material in the presence of a soluble salt of a compound obtained by condensing substantially one mol of formaldehyde with substantially two mols of betanaphthalene sulfonic acid.

7. The process of preparing colored concrete which comprises mixing water, hydraulic cement, and carbon black in the presence of a soluble salt of a compound obtained by condensing substantially one mol of formaldehyde with substantially two mols of beta-naphthalene sulfonic acid.

8. As a new composition of matter, colored concrete which contains a finely divided coloring material and a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

9. As a new composition of matter, colored concrete which contains a finely divided coloring material and a soluble sulfonic acid derivative of a compound having at least two naphthalene rings nucleus.

10. As a new composition of matter, colored concrete, which is prepared from hydraulic cement and which contains a finely divided coloring material and a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

11. As a new composition of matter, colored concrete which is prepared from hydraulic cement and which contains carbon black and a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

12. As a new composition of matter, colored concrete which is prepared from hydraulic cement and which contains finely divided iron oxide and a soluble compound obtained by condensing formaldehyde with a sulphonic acid of the naphthalene series.

13. As a new composition of matter, colored concrete which is prepared from hydraulic cement and which contains a finely divided coloring material and a soluble salt of a compound obtained by condensing substantially one mol of formaldehyde with substantially two mols of beta-naphthalene sulfonic acid.

14. As a new composition of matter, colored concrete which is prepared from hydraulic cement and which contains carbon black and a soluble salt of a compound obtained by condensing substantially one mol of formaldehyde with substantially two mols of beta-naphthalene sul- Ionic acid.

15. As a new composition of matter, a dry mixture which contains a calcareous substance, a finely divided coloring material, and a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

16. As a new composition of matter, a dry mixture which contains a calcareous substance, a finely divided coloring material, and a soluble sulfonic acid derivative of a compound having at least two naphthalene rings joined to the same carbon atom of an aliphatic nucleus.

17. As a new composition of matter, a dry mixture which contains hydraulic cement, a finely divided coloring material, and a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

18. As a new composition of matter, a dry mixture which contains hydraulic cement, carbon black, and a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene series.

'19. As a new composition of matter, a dry mixture which contains hydraulic cement, finely divided iron oxide, and a soluble compound obtained by condensing formaldehyde with a sulfonic acid of the naphthalene-series.

20. Asa new composition of matter, a dry mixture which contains hydraulic cement, a finely divided coloring material, and a soluble salt of a compound obtained by condensing substantially one mol of formaldehyde with substantially two mols of betal-naphthalene sulfonic acid.

21. As a new composition of matter, a dry mixture which contains hydraulic cement, carbon black, and a soluble salt of a compound obtained by condensing substantially one mol of formal- 145 dehyde with substantially two mols of betanaphthalene sulfonic acid.

GEORGE R. TUCKER. 

